1. Field of the Invention
The present invention relates to hand tools for attaching an electrical connector to the prepared end of a coaxial cable. More specifically, the present invention relates to hand tools that apply a very high level of compression force to the connector in a direction parallel to the axis of the connector and to hand tools that can be used to compress connectors of different sizes.
2. Description of Related Art
Coaxial cable is widely used to distribute radio and television signals, digital data and the like over large distribution networks. Large diameter coaxial cable is typically used in the main distribution links, with progressively smaller diameter cable being used as the ends of the distribution network are approached.
Connectors are attached at the ends of every coaxial cable link and large connectors are needed for the largest cables. One type of connector that is available is attached to the coaxial cable by applying a compression force to the connector parallel to the axis of the connector. This type of connector is designed with two parallel and opposed planar surfaces that are engaged by corresponding opposed planar compression surfaces on the hand tool.
As the handles of the tool are squeezed together, the compression surfaces on the hand tool move towards each other and apply a compression force to the connector. Typically, the compression force acts to move two parts of the connector into engagement or to collapse a portion of the connector into engagement with the coaxial cable.
Relatively high levels of compression force are needed to reliably attach large connectors and it is difficult for an installer to supply the necessary level of force when a conventionally designed hand tool is used. A hand tool capable of applying a very high level of compression force to the connector while requiring only limited hand force to operate the tool is needed for reliably attaching large connectors to large diameter coaxial cable.
Coaxial cable connectors come in a variety of sizes to match the different sizes of cables. A hand tool capable of attaching different sizes of connectors, particularly large diameter connectors, is needed to minimize the number of tools that must be carried by the installer.
To ensure reliable attachment of the connector to the coaxial cable it is important that the parallel planar surfaces of the connector remain parallel at all times as the hand tool squeezes those surfaces towards each other. If the compression tool allows the opposed compression surfaces to become misaligned as they move towards each other, the connector will not be properly compressed.
Prior art tools have difficulty in maintaining the correct parallel alignment. It is particularly difficult to maintain the correct alignment when applying very high compression forces, as needed for the largest connectors. A hand tool capable of accurately maintaining parallel alignment between the compression surfaces when applying high levels of compression force to large connectors is needed.
Even if the compression assembly tool is well designed to hold the compression surfaces in accurate parallel alignment, the connector must be accurately placed between the compression surfaces in the tool so that the axis of the connector is perpendicular to the plane of the compression surfaces. In addition, the connector must remain perpendicular to those surfaces throughout the compression cycle.
The farther apart the compression surfaces on the tool are when the compression cycle starts, the harder it is for the connector to be placed in the correct perpendicular alignment, and the easier it is for the connector to slip out of correct alignment during the compression cycle.
Existing compression assembly tool designs typically have a wide separation between the compression surfaces. These tools engage the connector at the front and back of the connector requiring a wide separation between the compression surfaces to accommodate the entire length of the connector. A hand tool with compression surfaces close together is desirable to ensure accurate initial placement of the connector between the compression surfaces and correct perpendicular connector alignment throughout the compression cycle.
In order to attach the largest connectors, which require the highest levels of compression force, prior art tools have conventionally been designed with very long handles. This requires clearance for the long handles to be operated and two hand operation. A tool capable of applying the required high levels of compression force with a single hand in a limited area would be desirable.
A related problem is that most prior art compression assembly tools can accept the connector to be compressed in only one direction. Typically, the coaxial cable must extend outward from the tool in a predetermined direction relative to the motion of the handles. This may create clearance problems with the tool handles if a connection is required in a limited space. A tool capable of being reversed relative to the connector would also be desirable.
Yet another related problem is that conventional compression assembly tools cannot attach splice connectors where coaxial cables extend outward in opposite directions from the connector. A tool adaptable for compressing splice connectors would also be desirable.